anonymous
  • anonymous
Find the exact values of cos 3 pi/4 radians sin 3 pi/4 radians HELP!
Mathematics
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
katieb
  • katieb
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
anonymous
  • anonymous
|dw:1371048646264:dw|
anonymous
  • anonymous
@UnkleRhaukus @terenzreignz @amistre64
anonymous
  • anonymous
@phi @ParthKohli @ganeshie8

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

phi
  • phi
first step is draw a circle and label the major angles: |dw:1371049226437:dw|
phi
  • phi
next, figure out where 3pi/4 is I think in degrees, so I would change it to degrees by multiplying by 180/pi you get \[ \frac{3 \pi}{4} \cdot \frac{180}{\pi} = 135 \]
phi
  • phi
|dw:1371049411930:dw|
anonymous
  • anonymous
It looks to be about 45 degrees or so.. @phi
phi
  • phi
it is 180-135 so you do not have to guess
anonymous
  • anonymous
Oh, then it is 45 degrees.
phi
  • phi
for convenience, we use a circle that has a radius of 1. we have |dw:1371049640319:dw| we have a 45-45-90 triangle
phi
  • phi
people expect you to memorize the sin , cos and tan of 45 degrees to get the correct sign. notice the sign of the x-axis is negative (because we are to the left of the origin) and the y-axis is positive (above the origin). the hypotenuse is always positive.
anonymous
  • anonymous
okay, but how do i get my answer?
phi
  • phi
first, what is the sin(45ยบ) ?
phi
  • phi
See http://www.mathsisfun.com/geometry/unit-circle.html and scroll down to the little table.
anonymous
  • anonymous
Sqrt 2 over 2
phi
  • phi
next, you need to figure out its sign sin(angle) = opposite / hypotenuse |dw:1371050352701:dw|
anonymous
  • anonymous
I don't know how to do that..
phi
  • phi
look at the picture. the side going up (the opposite side to the angle 45) is above the x-axis so it is positive. the hypotenuse is positive, so the signs are positive number / positive number . what sign do you get ?
anonymous
  • anonymous
A positive sign.?
phi
  • phi
yes
phi
  • phi
for the cosine, you use cos(angle) = adjacent/hypotenuse |dw:1371050609167:dw|
phi
  • phi
the cosine will have a negative number divided by a positive number
anonymous
  • anonymous
so it would be a negative sign. when solving the answer does the cosine variable come first or does the sin variable come first?
phi
  • phi
I would assume the answers are in the same order as the question Find the exact values of cos 3 pi/4 radians sin 3 pi/4 radians so cos, then sin
anonymous
  • anonymous
Okay, so I think my answer would either be my 1st choice or my 3rd choice.
phi
  • phi
yes. what sign is the cosine for this problem ? what sign is the sine ?
anonymous
  • anonymous
I think it would be answer choice 3 because the cosine is negative, and the sine would be positive.

Looking for something else?

Not the answer you are looking for? Search for more explanations.